Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1cf4eba3bb4fcdf…

MALICIOUS

PDF

94.3 KB Created: 2021-07-07 17:58:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0b81df2c3638ea4a20378b145192023e SHA-1: 9581511c9ed42616c585b35cf19da66cf246ea2d SHA-256: b1cf4eba3bb4fcdfd7aaeab1bf8b6f0f25b7a8988cd6055d9f99a71cc51fc6f8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous links to external websites, many hosted on compromised CMS platforms, suggesting a link farm designed to redirect users to malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a pattern of using disposable hosting for these links, further reinforcing the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://winston-woodward.com/wp-content/plugins/super-forms/uploads/php/files/7468d31a96d73a072e7db65b2081fb0b/20652858906.pdf
    • http://www.tobywells.org/media/fckdir/file/jajokawepa.pdf
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be9d12cb32e---regabakiwaw.pdf
    • http://toyotarent.kr/FileData/ckfinder/files/20210529_4233E4CEE06FCA95.pdf
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a321243b58a---4568610203.pdf
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ce0735ccdc9---tinekebiritesilumolo.pdf
    • http://sjar-tech.com/uploadfile/file///2021061718042412.pdf
    • http://apexnepaltravel.com/userfiles/file/62108147508.pdf
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083093965dba---22549665236.pdf
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/61gajkhoip73bvcpqnpu3bu1e2/81994017294.pdf
    • http://woodwork.pl/ubezpiecz/obrazy/file/58378111093.pdf
    • http://sungsam.net/userData/board/file/dezumenejuxiwimim.pdf
    • http://boathousebrokerage.com/userfiles/file/wiwupija.pdf
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609d4bff68c0e---45278088934.pdf
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1609480dd66468---bilatijupiwafo.pdf
    • http://transinfosoft.com/userfiles/file/dibuzosokinatezusubog.pdf
    • http://gorisum.net/fckeditor/upload_file/file/52603500700.pdf
    • http://bhk-aindling.com/userfiles/files/tizagujix.pdf
    • https://www.alpha-dynamics.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1607602e8104d4---vorep.pdf
    • http://rufullthrottle.com/wp-content/plugins/formcraft/file-upload/server/content/files/160821c1e8ecb6---84277529240.pdf
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bae81f22cf4---suworu.pdf
    • https://roweryelectra.eu/app/webroot/uploads/file/16219007312427.pdf
    • http://yjccnc.com/upload/files/10858356339.pdf
    • http://santeh.md/img/files/fedimamosegedowisuti.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=breaking+rules+synonym
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010c5b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C5B 16792 bytes
font_01_sfnt_off00012472.bin
17a355975b223fc3830e0975423ca68fd54ff302c0474b94c521474b612bfaed
pdf-font-stream PDF embedded font (sfnt) at offset 0x12472 10712 bytes
font_02_sfnt_off00013d09.bin
960a349b1c64fc08e27c82dfb81db4ea36d5f09c837d56d383af5d727078fdf7
pdf-font-stream PDF embedded font (sfnt) at offset 0x13D09 18620 bytes